This invention relates to novel mixtures of brominated diphenyl ethanes, which mixtures impart good flame retardancy to acrylonitrile-butadine-styrene (ABS) based formulations.
ABS based formulations are used widely in the manufacture of pipes, automobile parts, and housings for business machine and telephones. In many of these uses, it is required that the articles have a flame retardant quality. Such quality can be obtained by incorporating a flame retardant, e.g. a mixture of brominated diphenyl oxides, in the formulation. Especially useful brominated diphenyl oxide mixtures are those which have an average of from about 7.0 to about 7.7 bromine atoms per molecule of diphenyl oxide and which contain 0-2 weight percent pentabromodiphenyl oxide, 5-15 weight percent hexabromodiphenyl oxide, 40-55 weight percent heptabromodiphenyl oxide, 30-40 weight percent octabromodiphenyl oxide, 5-15 weight percent nonabromodiphenyl oxide, and 0-2 weight percent decabromodiphenyl oxide. These mixtures are commercially available or can be easily prepared by the reaction of bromine with diphenyl oxide in the presence of a bromination catalyst, such as, ZrCl.sub.4. See U.S. Pat. No. 4,740,629.
While these mixtures give ABS based formulations a flame retardant quality, they are not a panacea as their presence can reduce the impact strength of articles made from such formulations.